By combining the powers of two single-atom-thick carbon structures, researchers at the George Washington Univ.'s Micro-propulsion and Nanotechnology Laboratory have created a new ultracapacitor that is both high performance and low cost. The device capitalizes on the synergy brought by mixing graphene flakes with single-walled carbon nanotubes, two carbon nanostructures with complementary properties.
A bullet fired through a block of wood will slow...
Researchers in Ireland have used a simple method...
Researchers in Pennsylvania and Texas have shown the ability to grow high quality, single-layer materials one on top of the other using chemical vapor deposition. This highly scalable technique, often used in the semiconductor industry, can produce materials with unique properties that could be applied to solar cells, ultracapacitors for energy storage, or advanced transistors for energy efficient electronics, among many other applications.
It’s an obvious truism, but one that may soon be outdated: The problem with solar power is that sometimes the sun doesn’t shine. Now a team at Massachusetts Institute of Technology and Harvard Univ. has come up with an ingenious workaround: a material that can absorb the sun’s heat and store that energy in chemical form, ready to be released again on demand.
Nanoengineering researchers at Rice Univ. and Nanyang Technological Univ. in Singapore have unveiled a potentially scalable method for making one-atom-thick layers of molybdenum diselenide—a highly sought semiconductor that is similar to graphene but has better properties for making certain electronic devices like switchable transistors and light-emitting diodes.
A new theoretical study shows the conductivity conditions under which graphene nanoribbons can become switches in externally controlled electronic devices. The results, obtained by researchers in Argentina and Brazil, yield a clearer theoretical understanding of conductivity in graphene samples of finite size, which have applications in externally controlled electronic devices.
Carbon nanotubes are reinforcing bars that make 2-D graphene much easier to handle in a new hybrid material grown by researchers at Rice Univ. The Rice laboratory of chemist James Tour set nanotubes into graphene in a way that not only mimics how steel rebar is used in concrete but also preserves and even improves the electrical and mechanical qualities of both.
As the properties and applications of graphene continue to be explored in laboratories all over the world, a growing number of researchers are looking beyond the one-atom-thick layer of carbon for alternative materials that exhibit similarly captivating properties.
Recent research in Japan, China and U.S. has revealed through theoretical simulations that the molecular mechanism of carbon nanotube growth and hydrocarbon combustion actually share many similarities. In studies using acetylene molecules as feedstock, a highly reactive molecular intermediate was found to play an important role in both processes forming CNTs and soot, which are two distinctively different structures.
A research team led by SLAC National Accelerator Laboratory scientists has uncovered a potential new route to produce thin diamond films for a variety of industrial applications, from cutting tools to electronic devices to electrochemical sensors. The scientists added a few layers of graphene to a metal support and exposed the topmost layer to hydrogen.
Lithium-ion batteries power a vast array of modern devices, from cell phones, laptops, and laser pointers to thermometers, hearing aids, and pacemakers. The electrodes in these batteries typically comprise three components: active materials, conductive additives, and binders. Now, a team of researchers at the Univ. of Delaware has discovered a “sticky” conductive material that may eliminate the need for binders.
Nanotechnology is advancing tools likened to Star Trek's "tricorder" that perform on-the-spot chemical analysis for a range of applications including medical testing, explosives detection and food safety. Researchers found that when paper used to collect a sample was coated with carbon nanotubes, the voltage required was 1,000 times reduced, the signal was sharpened and the equipment was able to capture far more delicate molecules.
Vertically aligned carbon nanofibers (VACNFs) are a commonly manufactured material, but conventional techniques for creating them have relied on the use of ammonia gas, which is toxic. Though it not costly, it is also not free, either. Researchers in North Carolina have demonstrated that VACNFs can be manufactured using ambient air, making the manufacturing process safer and less expensive.
Researchers in California have used a beam of intense ultraviolet light to look deep into the electronic structure of a material made of alternating layers of graphene and calcium. While it's been known for nearly a decade that this combined material is superconducting, the new study offers the first compelling evidence that the graphene layers are instrumental in this process. The finding could lead to super-efficient nanoelectronics.
Engineers would love to create flexible electronic devices, such as e-readers that could be folded to fit into a pocket. One approach they are trying involves designing circuits based on electronic fibers, known as carbon nanotubes, instead of rigid silicon chips. But reliability is essential.
The first room-temperature light detector that can sense the full infrared spectrum has the potential to put heat vision technology into a contact lens. Unlike comparable mid- and far-infrared detectors currently on the market, the detector developed by Univ. of Michigan engineering researchers doesn't need bulky cooling equipment to work.
Researchers have discovered that creating a graphene-copper-graphene “sandwich” strongly enhances the heat conducting properties of copper, a discovery that could further help in the downscaling of electronics.
Light can trigger coordinated, wave-like motions of atoms in atom-thin layers of crystal, scientists have shown. The waves, called phonon polaritons, are far shorter than light waves and can be "tuned" to particular frequencies and amplitudes by varying the number of layers of crystal, they report.
The huge surface area and strong interactions between graphene layers causes facile “stacking” behavior that dramatically reduces available surface area, inhibiting graphene electronic properties. Researchers have tried to prevent this with carbon black, but this also carries undesirable property changes. By introducing protuberances on graphene during synthesis, researchers in China have found a solution to the stacking problem.
A team of researchers has developed a material that could help prevent blood clots associated with catheters, heart valves, vascular grafts and other implanted biomedical devices. Blood clots at or near implanted devices are thought to occur when the flow of nitric oxide, a naturally occurring clot-preventing agent generated in the blood vessels, is cut off. When this occurs, the devices can fail.
Tear apart an electric car's rechargeable battery and you'll find a mineral normally associated with No. 2 pencils. It's graphite. And experts say the promise of expanded uses for "pencil lead" in lithium-ion batteries, as well as a decrease in supply from China, has helped touch off the largest wave of mining projects in decades.
Last year, a physicist and a mechanical engineer at Northeastern Univ. combined their expertise to integrate electronic and optical properties on a single electronic chip, enabling them to switch electrically using light alone. Now, they have built three new devices that implement this fast technology: an AND-gate, an OR-gate and a camera-like sensor made of 250,000 miniature devices.
Every second, your computer must process billions of computational steps to produce even the simplest outputs. Imagine if every one of those steps could be made just a tiny bit more efficient. A Northeastern Univ. team has developed a series of novel devices that do just that. The team combined their expertise to unearth a physical phenomenon that could usher in a new wave of highly efficient electronics.
Researchers at Argonne National Laboratory in collaboration with scientists at Northwestern Univ. are the first to grow graphene on silver which, until now, posed a major challenge to many in the field. Part of the issue has to do with the properties of silver, the other involves the process by which graphene is grown.
Researchers have devised a way of making tiny holes of controllable size in sheets of graphene, a development that could lead to ultra-thin filters for improved desalination or water purification. The team of researchers succeeded in creating subnanoscale pores in a sheet of the one-atom-thick material, which is one of the strongest materials known.
Previous efforts to create graphene nanoribbons followed a top-down approach, using lithography and etching process to try to cut ribbons out of graphene sheets. Cutting ribbons 2 nm-wide is not practical, however, and these efforts have not been very successful. Now, a research team has developed a chemical approach to mass producing these graphene nanoribbons. This process that may provide an avenue to harnessing graphene's conductivity.
A single-walled carbon nanotube grows from the round cap down, so it’s logical to think the cap’s formation determines what follows. But according to researchers at Rice Univ., that’s not entirely so. Theoretical physicist Boris Yakobson and his Rice colleagues found through exhaustive analysis that those who wish to control the chirality of nanotubes would be wise to look at other aspects of their growth.
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